Lightning-akrester



W. REID.

LIGHTNING ARRESTER.

APPLICATION FILED DEC-14. 1918.

1,8 1 1 ,9 1 6. Patented Aug. 5, 1919.

W W n W" I! E m I l nl lllll ZHL/EZZZUJ'Z' T all whom it may concern:

UNITED STATES PATENT, oFFIo WILLIAM REID, OF CHICAGO, ILLINOIS.

LIGHTNING-ARRESTER.

' Specification of batters Patent.

Application filed December 14, 1918. Serial No. 266,803.

. Be it lmown that I, WILLIAM REID, a citizen of the UnitedStates,residing at Chicago, in .the county of Cook and State 'of Illinois, haveinvented new and useful 1mprovements in Lightning Arr'esters, of whichthe following is a full, clear, concise, and exact description,reference being had to the accompanying drawing, forming a part of thisspecification. r

This invention relates to lightningarresters, and, more particularly, tolightning arresters provided with a protected sparkgap.

' production of an improved form oflight- 'ning arrester in which theground-plate and the associated spark lates are located so as to bereadily accessible and always visible, but which are at the same timeprotected to avoid the deleterious results which would occur because ofthe lowering of the resistance of the air-gap due to the accumulation inand about said air-gap of dust, cinders, bugs, etc. The protection ofthe spark-gap against such foreign matter which might tend to reduce theresistance of said gap, or even completely short-circuit it, is veryimportant, especially when lightning arresters of this type are utilizedin places where the air is frequently charged with large volumesof suchinjurious foreign matter. A typical example of such a case is found inthe circuits for signaling and communication used in, about, and along arailroad right-ofway, in which case the lightning arrester is frequentlyexposed to an atmosphere charged with cinders, dust,etc.

Other objects of the invention will become apparent from the followingdescription, the accompanying drawings, and the appended claims. v

For the sake of illustrating my invention,

a preferred form thereof is illustrated in the accompanying drawings, inwhich Figurel represents in perspective a lightning arrester of theimproved type illustrating the method used for protecting the airgap;and K Patented Aug. 5, 1919. i

Fig. 2 is a vertical central section taken on the plane represented bythe line 22 of Fig. 1.

s illustrated inthe drawings, the lightning arrester consists of amassive piece of insulating material 10, preferable of porce lain, thisconstituting the body of the arrester. I with two projecting lugs orears 11 and 12 This body portion 10' is provided fitted with suitableapertures 13 and 14, respectively, which serve to receive the mountingscrews for mounting the arrester. The body 10 of the arrester containsthree internal apertures 15, 16, and 17 the apertures or recesses 15 and17 being'fitted with choke or induction coils 18 and 19, respectively,and the contact plates 20 and 21, respectively.

Each of the choke-coils 18 and 19 is conductively attached to itsrespective contact plate 20 or 21, and the contact plates 20 and 21 areintegral with the long screw threaded shanks 22 and 23, respectively.The shanks 22 and 23 constitute the conductors for interconnecting theline wires with the chokecoils 18 and 19.

The upper face of the body 10 of the porcelain base is fitted with anaperture 26, in

which is positioned the ground-plate 27-conductively secured to thescrew-threaded shank 28 of a screw 29 having a head 30 which is fittedin the aperture 16 in the lower portion of the porcelain base. The\ground plate 27 is held in position on the screw 29 between anupwardly-extending portion 31 in the aperture 26, which constitutes amounting base for the ground-plate 27, the ground-plate being heldagainst this base by a securing nut 32. The screw 29 thereforeconstitutes the ground terminal post, said post extending well above theupper face of the porcelain base 10. Likewise fitted in theaperture 26are the two spark-plates 35 and 36, preferably constructed of brass andhaving saw-toothed notched edges, the spark- :7.

plates being bent at right-angles, as indi cated at 37 and, 38,respectively, so that the saw-toothed front edge thereof will rest wellbelow the upperface of the porcelain body 10, and so that they will bein close proximity in the ground-plate 27. The spark plates and 36 aremounted in suitable grooves on the top face of the body 10 and are heldin position and conductively connected to the upwardly-extending shanks22 and 23 of the line terminal posts and all,

s respectively, by means of the securing nuts of the ground terminalpost 29. The plate s5 is preferably made transparent and is usuallyconstructed of glass or mica. As indicated in Fig. 2 the plate 45 ispreferably made long enough so as to extend beyond the side wall of theaperture 26, said plate resting on the spark-plates 35 and 36, in whichposition it is securely fastened by a positioning nut 46 coiiperatingwith the ground terminal post 29. The spark-plates 35 and 36 arepreferably fitted with elongated slots through which the line terminalposts 40 and ll pass, whereby said plates are capable of a slightadjustment for the purpose of determining and properly adjusting thesize of the spark-gap for the particular line conditions which are to bemet.

The conductor leads are obviously secured to the line terminal posts -10and all by means of a binding-nut of any suitable type, and in a likemanner the ground connection is secured to the ground terminal post 29.The choke-coils 18 and 19 are interconnected serially by means of thelead 47. The arrester is serially connected in the line circuit, andwhen thus connected it will be obvious that the circuit will extend fromone line post terminal, for example it), through the shank 22 thereof,the choke-coil '18, the lead 47, the choke-coil 19, the shank 23, to theother line post terminal 41, and thence to the apparatus rotected.

Likewise, it will be apparent from the foregoing description that thetwo sparkplates 35 and 36 are in multiple with this connection, andthrough the air-gap this multiple connection leads to ground by way ofthe ground-plate 27, the ground post terminal 29, and a suitable groundlead.

The electrical operation of this type of apparatus is well known tothose skilled in the art and no further description is consequentlyrequired,

It will be evident from the improved form of construction herein beforedescribed that,

with lightning arresters of this type the spark-gap is absolutelyinclosed within the aperture 26 and thus is entirely free from thedisturbing influence of foreign matter and impurities which may be inthe atmosphere and which, consequently, if the gap were not protected,might be lodged in or about the ground-plate and its associatedappurtenances. Due to the protection of the plate d5, however, foreignmatter will rest on the late and cannot reach the electrical connectionstherebeneath. Likewise, in the preferred form of the invention, in whichthe plate is made of transparent material, the ground-plate and itsassociated spark-plate are always clearly visible for inspect-ionpurposes without in any way disturbing the arrester equipment Likewise,if for any reason it is desired to get at the ground-plate and itsassociated apparatus, this is very readily and quickly accomplished bymerely removing the holding nut 46 and raising the rotecting platedS,when all the apparatus within the aperture 26 is readily accessible.

Lightning arresters constructed in accordance with the teachings ofthis'invention are, consequently, very advantageous, because of thecombined effect of completely protecting the spark-gap and at the sametime making it so readily accessible and always visible.

Obviously, the invention is not limited to the preferred form thereofherein illustrated and described, but is capable of many alterations andvariations, all coming within the spirit and scope of the invention asset forth in the following claims.

ll claim, etc.

1. A lightning arrester comprising, in combination, an insulating base,apertures in said base, cl1oke-coils in each of said apertures, exposedline terminals connected With said coils, an aperture positioned betweensaid line terminals, a ground connection located in said last-mentionedaperture, conducting bars connected to said line terminals and extendinginto said last-mentioned aperture and in close proximity to said groundterminal and means to cover said aperture to inclose said groundterminal and the adjacent portions of said conducting bars.

2. A lightning arrester comprising, in combination, an insulating base,line conductors mounted on said base, a ground terminal mounted on saidbase, conducting means extending from said line terminal to said groundterminal into close proximity with each other, an aperture in said baseto inclose the adjacent portions of said conducting means, and means tocover said aperture to protect the apparatus therein from externalinfluences.

3. A lightning arrester comprising, in combination, an insulating base,sparlcplates mounted on the top face of said base, an

aperture in the top face of said base, a

ground terminal fitted in said apertureand extending above the top faceof said base, a ground-plate and spark-gap plate extensions ill) iz o

extending into and being inclosed in said I aperture below the top faceof said base, and a transparent means mounted on the top face of saidbase to completely cover said aperture;

4. A lightning arrester comprising, in combination, an insulating base,line terminals and a ground terminal mounted on said base, choke-coilsconductively connected to said line terminals and serially intercon- 10nected, a spark-gap aperture positioned in the top face of said base, aground-plate in said aperture, and a transparent cover-plate for saidaperture.

In Witness whereof, I have hereunto sub- 15 scribed my name.

' WILLIAM REID.

